SYNOPSIS
git mergetool [--tool=<tool>] [-y | --[no-]prompt] [<file>…]
DESCRIPTION
Use git
mergetool
to run one of several merge utilities to resolve
merge conflicts. It is typically run after git merge.
If one or more <file> parameters are given, the merge tool program will be run to resolve differences in each file (skipping those without conflicts). Specifying a directory will include all unresolved files in that path. If no <file> names are specified, git mergetool will run the merge tool program on every file with merge conflicts.
OPTIONS
- -t <tool>
- --tool=<tool>
-
Use the merge resolution program specified by <tool>. Valid values include emerge, gvimdiff, kdiff3, meld, vimdiff, and tortoisemerge. Run
git
mergetool
--tool-help
for the list of valid <tool> settings.If a merge resolution program is not specified, git mergetool will use the configuration variable
merge.tool
. If the configuration variablemerge.tool
is not set, git mergetool will pick a suitable default.You can explicitly provide a full path to the tool by setting the configuration variable
mergetool.
<tool>.path
. For example, you can configure the absolute path to kdiff3 by settingmergetool.kdiff3.path
. Otherwise, git mergetool assumes the tool is available in PATH.Instead of running one of the known merge tool programs, git mergetool can be customized to run an alternative program by specifying the command line to invoke in a configuration variable
mergetool.
<tool>.cmd
.When git mergetool is invoked with this tool (either through the
-t
or--tool
option or themerge.tool
configuration variable), the configured command line will be invoked with$BASE
set to the name of a temporary file containing the common base for the merge, if available;$LOCAL
set to the name of a temporary file containing the contents of the file on the current branch;$REMOTE
set to the name of a temporary file containing the contents of the file to be merged, and$MERGED
set to the name of the file to which the merge tool should write the result of the merge resolution.If the custom merge tool correctly indicates the success of a merge resolution with its exit code, then the configuration variable
mergetool.
<tool>.trustExitCode
can be set totrue
. Otherwise, git mergetool will prompt the user to indicate the success of the resolution after the custom tool has exited. - --tool-help
-
Print a list of merge tools that may be used with
--tool
. - -y
- --no-prompt
-
Don’t prompt before each invocation of the merge resolution program. This is the default if the merge resolution program is explicitly specified with the
--tool
option or with themerge.tool
configuration variable. - --prompt
-
Prompt before each invocation of the merge resolution program to give the user a chance to skip the path.
- -g
- --gui
-
When git-mergetool is invoked with the
-g
or--gui
option, the default merge tool will be read from the configuredmerge.guitool
variable instead ofmerge.tool
. Ifmerge.guitool
is not set, we will fallback to the tool configured undermerge.tool
. This may be autoselected using the configuration variablemergetool.guiDefault
. - --no-gui
-
This overrides a previous
-g
or--gui
setting ormergetool.guiDefault
configuration and reads the default merge tool from the configuredmerge.tool
variable. - -O<orderfile>
-
Process files in the order specified in the <orderfile>, which has one shell glob pattern per line. This overrides the
diff.orderFile
configuration variable (see git-config(1)). To canceldiff.orderFile
, use-O/dev/null
.
CONFIGURATION
Everything below this line in this section is selectively included from the git-config(1) documentation. The content is the same as what’s found there:
- mergetool.<tool>.path
-
Override the path for the given tool. This is useful in case your tool is not in the PATH.
- mergetool.<tool>.cmd
-
Specify the command to invoke the specified merge tool. The specified command is evaluated in shell with the following variables available: BASE is the name of a temporary file containing the common base of the files to be merged, if available; LOCAL is the name of a temporary file containing the contents of the file on the current branch; REMOTE is the name of a temporary file containing the contents of the file from the branch being merged; MERGED contains the name of the file to which the merge tool should write the results of a successful merge.
- mergetool.<tool>.hideResolved
-
Allows the user to override the global
mergetool.hideResolved
value for a specific tool. Seemergetool.hideResolved
for the full description. - mergetool.<tool>.trustExitCode
-
For a custom merge command, specify whether the exit code of the merge command can be used to determine whether the merge was successful. If this is not set to true then the merge target file timestamp is checked, and the merge is assumed to have been successful if the file has been updated; otherwise, the user is prompted to indicate the success of the merge.
- mergetool.meld.hasOutput
-
Older versions of
meld
do not support the--output
option. Git will attempt to detect whethermeld
supports--output
by inspecting the output ofmeld
--help
. Configuringmergetool.meld.hasOutput
will make Git skip these checks and use the configured value instead. Settingmergetool.meld.hasOutput
totrue
tells Git to unconditionally use the--output
option, andfalse
avoids using--output
. - mergetool.meld.useAutoMerge
-
When the
--auto-merge
is given, meld will merge all non-conflicting parts automatically, highlight the conflicting parts, and wait for user decision. Settingmergetool.meld.useAutoMerge
totrue
tells Git to unconditionally use the--auto-merge
option withmeld
. Setting this value toauto
makes git detect whether--auto-merge
is supported and will only use--auto-merge
when available. A value offalse
avoids using--auto-merge
altogether, and is the default value. - mergetool.<vimdiff variant>.layout
-
Configure the split window layout for vimdiff’s <variant>, which is any of
vimdiff
,nvimdiff
,gvimdiff
. Upon launchinggit
mergetool
with--tool=
<variant> (or without--tool
ifmerge.tool
is configured as <variant>), Git will consultmergetool.
<variant>.layout
to determine the tool’s layout. If the variant-specific configuration is not available,vimdiff
's is used as fallback. If that too is not available, a default layout with 4 windows will be used. To configure the layout, see theBACKEND
SPECIFIC
HINTS
section. - mergetool.hideResolved
-
During a merge, Git will automatically resolve as many conflicts as possible and write the MERGED file containing conflict markers around any conflicts that it cannot resolve; LOCAL and REMOTE normally represent the versions of the file from before Git’s conflict resolution. This flag causes LOCAL and REMOTE to be overwritten so that only the unresolved conflicts are presented to the merge tool. Can be configured per-tool via the
mergetool.
<tool>.hideResolved
configuration variable. Defaults tofalse
. - mergetool.keepBackup
-
After performing a merge, the original file with conflict markers can be saved as a file with a .
orig
extension. If this variable is set tofalse
then this file is not preserved. Defaults totrue
(i.e. keep the backup files). - mergetool.keepTemporaries
-
When invoking a custom merge tool, Git uses a set of temporary files to pass to the tool. If the tool returns an error and this variable is set to
true
, then these temporary files will be preserved; otherwise, they will be removed after the tool has exited. Defaults tofalse
. - mergetool.writeToTemp
-
Git writes temporary BASE, LOCAL, and REMOTE versions of conflicting files in the worktree by default. Git will attempt to use a temporary directory for these files when set
true
. Defaults tofalse
. - mergetool.prompt
-
Prompt before each invocation of the merge resolution program.
- mergetool.guiDefault
-
Set
true
to use themerge.guitool
by default (equivalent to specifying the--gui
argument), orauto
to selectmerge.guitool
ormerge.tool
depending on the presence of aDISPLAY
environment variable value. The default isfalse
, where the--gui
argument must be provided explicitly for themerge.guitool
to be used.
TEMPORARY FILES
git
mergetool
creates *.orig
backup files while resolving merges.
These are safe to remove once a file has been merged and its
git
mergetool
session has completed.
Setting the mergetool.keepBackup
configuration variable to false
causes git
mergetool
to automatically remove the backup files as files
are successfully merged.
BACKEND SPECIFIC HINTS
vimdiff
Description
When specifying --tool=vimdiff
in git
mergetool
Git will open Vim with a 4
windows layout distributed in the following way:
------------------------------------------ | | | | | LOCAL | BASE | REMOTE | | | | | ------------------------------------------ | | | MERGED | | | ------------------------------------------
LOCAL
, BASE
and REMOTE
are read-only buffers showing the contents of the
conflicting file in specific commits ("commit you are merging into", "common
ancestor commit" and "commit you are merging from" respectively)
MERGED
is a writable buffer where you have to resolve the conflicts (using the
other read-only buffers as a reference). Once you are done, save and exit Vim as
usual (:wq
) or, if you want to abort, exit using :cq
.
Layout configuration
You can change the windows layout used by Vim by setting configuration variable
mergetool.vimdiff.layout
which accepts a string where the following separators
have special meaning:
-
+
is used to "open a new tab" -
,
is used to "open a new vertical split" -
/
is used to "open a new horizontal split" -
@
is used to indicate the file containing the final version after solving the conflicts. If not present,MERGED
will be used by default.
The precedence of the operators is as follows (you can use parentheses to change it):
`@` > `+` > `/` > `,`
Let’s see some examples to understand how it works:
-
layout
=
"(LOCAL,BASE,REMOTE
)/MERGED
"This is exactly the same as the default layout we have already seen.
Note that
/
has precedence over,
and thus the parenthesis are not needed in this case. The next layout definition is equivalent:layout = "LOCAL,BASE,REMOTE / MERGED"
-
layout
=
"LOCAL,MERGED,REMOTE"If, for some reason, we are not interested in the
BASE
buffer.------------------------------------------ | | | | | | | | | LOCAL | MERGED | REMOTE | | | | | | | | | ------------------------------------------
-
layout
=
"MERGED"Only the
MERGED
buffer will be shown. Note, however, that all the other ones are still loaded in vim, and you can access them with the "buffers" command.------------------------------------------ | | | | | MERGED | | | | | ------------------------------------------
-
layout
=
"@LOCAL,REMOTE"When
MERGED
is not present in the layout, you must "mark" one of the buffers with an asterisk. That will become the buffer you need to edit and save after resolving the conflicts.------------------------------------------ | | | | | | | | | | LOCAL | REMOTE | | | | | | | | | | ------------------------------------------
-
layout
=
"LOCAL,BASE,REMOTE/
MERGED
+
BASE,LOCAL
+
BASE,REMOTE
"Three tabs will open: the first one is a copy of the default layout, while the other two only show the differences between (
BASE
andLOCAL
) and (BASE
andREMOTE
) respectively.------------------------------------------ | <TAB #1> | TAB #2 | TAB #3 | | ------------------------------------------ | | | | | LOCAL | BASE | REMOTE | | | | | ------------------------------------------ | | | MERGED | | | ------------------------------------------
------------------------------------------ | TAB #1 | <TAB #2> | TAB #3 | | ------------------------------------------ | | | | | | | | | | BASE | LOCAL | | | | | | | | | | ------------------------------------------
------------------------------------------ | TAB #1 | TAB #2 | <TAB #3> | | ------------------------------------------ | | | | | | | | | | BASE | REMOTE | | | | | | | | | | ------------------------------------------
-
layout
=
"LOCAL,BASE,REMOTE/
MERGED
+
BASE,LOCAL
+
BASE,REMOTE
+
(LOCAL/BASE/REMOTE
),MERGED
"Same as the previous example, but adds a fourth tab with the same information as the first tab, with a different layout.
--------------------------------------------- | TAB #1 | TAB #2 | TAB #3 | <TAB #4> | --------------------------------------------- | LOCAL | | |---------------------| | | BASE | MERGED | |---------------------| | | REMOTE | | ---------------------------------------------
Note how in the third tab definition we need to use parentheses to make
,
have precedence over/
.
Variants
Instead of --tool=vimdiff
, you can also use one of these other variants:
-
--tool=gvimdiff
, to open gVim instead of Vim. -
--tool=nvimdiff
, to open Neovim instead of Vim.
When using these variants, in order to specify a custom layout you will have to
set configuration variables mergetool.gvimdiff.layout
and
mergetool.nvimdiff.layout
instead of mergetool.vimdiff.layout
(though the
latter will be used as fallback if the variant-specific one is not set).
In addition, for backwards compatibility with previous Git versions, you can
also append 1
, 2
or 3
to either vimdiff
or any of the variants (ex:
vimdiff3
, nvimdiff1
, etc…) to use a predefined layout.
In other words, using --tool=
[g,n,
]vimdiffx
is the same as using
--tool=
[g,n,
]vimdiff
and setting configuration variable
mergetool.
[g,n,
]vimdiff.layout
to…
-
x=1
: "@LOCAL,REMOTE
" -
x=2
: "LOCAL,MERGED,
REMOTE
" -
x=3
: "MERGED"
Example: using --tool=gvimdiff2
will open gvim
with three columns (LOCAL,
MERGED and REMOTE).
GIT
Part of the git(1) suite